1. Field of the Invention
The present invention relates to a new π-conjugated polymer useful as a material for organic electronics such as photoelectric conversion elements, FET elements and light-emitting elements and a manufacturing method of the π-conjugated polymer.
2. Description of the Related Art
Since π-conjugated polymers have π-electron system extended one-dimensionally along the main chains, they exhibit unique electronic and optical features. The most typical examples are conductive polymers; however, applications of these π-conjugated polymers are actively spread not only for use as a conductive material but also to various function elements such as photoelectric conversion elements, FET elements and light-emitting elements in recent years. The organic polymers are used because of low production cost, sufficient flexibility, strength and lightweight, capability of having larger dimension and possibility of a broad range of designs on the molecular level.
Typical examples of π-conjugated polymer include polyacetylene, poly-p-phenylene, polythiophene, polyallylenevinylene, and the like. Because of diverseness of molecular designs in recent years, various π-conjugated polymers are being examined aiming for more sophisticated elements. Many proposals have been made, for example, poly(alkyl)thiophene (Appl. Phys. Lett., 69 4108 (1996)) and polymers having fluorene structure as a basic structural unit (U.S. Pat. No. 5,777,070). In particular, π-conjugated polymers in U.S. Pat. No. 5,777,070 are actively applied to FET elements.
Furthermore, polymer materials having alylamine unit as a repeating unit are also being examined (Japanese Patent Application Laid-Open (JP-A) Nos. 10-310635, 08-157575, 2002-515078, International Publication No. WO97/09394, Synth. Met., 84 269 (1997)).
And polymers having carbon-carbon triple bond are being examined energetically (JP-A Nos. 06-166743, 2000-344873, Macromol. Chem. Phys. 202 2572 (2001), Chem. Rev. 100 605 (2000)).
The mobility, a typical parameter of the materials for organic electronics, of the polymer materials in these related arts has been improved remarkably. However, polymers of higher mobility are still desired considering the application to organic FET elements as materials for organic electronics.
In order to utilize the most important features such as low production cost, sufficient flexibility and strength, lightweight and capability of having larger dimension as an element using organic materials, a sufficient solubility in organic solvent is needed. Generally, the structure of π-conjugated polymers in which conjugation is stretched is often rigid, and this lead to lowering of solubility. Therefore in the current situation, many polymer materials in above related arts are not satisfactory in terms of solubility and various molecular designs are being examined to avoid this problem.